Impact resistant modular braille display device

ABSTRACT

Disclosed is a braille display that is impact resistant and that employs a modular construction. The impact resistance is achieved, in part, by molded and resilient end caps. Each end cap includes a centrally positioned slit that functions in absorbing lateral impacts to the display. The impact resistance is further achieved by an over molded housing that is positioned about an associated USB connector. The modularity of the display is achieved by way of a subassembly that is releasably secured within the interior of a main housing. The subassembly, in turn, includes a series of cell compartments that are arranged in groups. Each group of cell compartments is controlled by an individual shift register. This allows a grouping cell compartments to be removed and replaced as needed without disturbing the remaining cell components.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority to,application Ser. No. 16/747,858, filed on Jan. 21, 2021, entitled“Impact Resistant Modular Braille Display Device,” now U.S. Pat. No.11,062,623, issued Jul. 13, 2021, which itself is a continuation of, andclaims priority to, application Ser. No. 15/627,599, filed on Jun. 20,2017, entitled “Impact Resistant Modular Braille Display Device,” nowU.S. Pat. No. 10,540,909, issued Jan. 21, 2020, the contents of which isfully incorporated herein for all purposes.

BACKGROUND OF THE INVENTION Field of the Invention

This disclosure relates to a braille display device. More particularly,the disclosure relates to an impact resistant display device thatemploys a modular construction.

Description of the Background Art

A braille display is an electromechanical device that connects to aperipheral device, such as a computer or a monitor, by way of a wired orwireless connection. Braille displays are used to convert textcharacters from the peripheral device into braille characters that canbe perceived by a blind or low vision user. Computer software can beused to convert both text and visual images into braille characters thatcan be read by the user. Braille displays consist of a line of tactilecells. Typical displays include an array of 20, 40, or 80 tactile cells.Each individual cell corresponds to a single braille characterconsisting of six or eight tactile pins that move up and down inresponse to an instruction signal. Braille characters are generated byraising certain pins above and keeping others below a tactile surface.The tactile pins can be driven by mechanical, electromechanical,piezoelectric, pneumatic, or magnetic effects. When in the raisedposition, the pins extend above the tactile surface and can be felt by auser. The cells of the array together represent a line of text. After aline of text has been read the user, the display can be refreshed toallow for additional lines to be presented and read.

Although tactile pins can be driven in a number of different ways, it iswell known in the art to drive the pins via piezoelectric reeds or otherelectromechanical drivers. The instruction signal for an 8 pin cellwould include 8 inputs corresponding to an up or down instruction foreach pin. These instructions would be provided as correspondingelectrical inputs to the electromechanical driver. If piezoelectricreeds are used, the electrical inputs actuate the reeds to cause certaintactile pins to protrude above a tactile surface, thereby allowing aspecific braille character to be displayed.

An example of braille display is disclosed by U.S. Pat. No. 6,417,821 toBecker et al. Becker discloses a tactual computer monitor with rows andcolumns of rectangular cells. Each cell includes four rows and twocolumns of movable pins that can be read by a blind person. The pins aredriven by electromechanical impact drivers.

Another example is disclosed by U.S. Pat. No. 4,266,936 to Rose. Rosediscloses a portable braille display unit that is the size of aconventional braille page. Each braille character is displayed by abraille cell module that includes spring actuated pins that arecontrolled by bimetallic latches. To display the braille characters, anelectrical current applied to resistively heat selected bimetalliclatches. In response, the bimetallic latches bend and disengage from thepin, allowing a compressive spring to move the pin upwardly through asurface plate to display a braille dot.

The braille cells of the type discussed above are not durable and tendto be fragile. This fragile construction results in the display'smalfunctioning upon being dropped or impacted. In particular, impacts toknown displays often result in the electromechanical elements becomingmisaligned, which in turn, precludes the proper operation of the tactilepins. In some cases, the pins fail to extend above the tactile surfaceupon actuation, and they likewise fail to fully retract below thesurface when disengaged. For this reason, most known displayconstructions are designed for static, desktop uses. In suchenvironments, the display device is unlikely to encounter the type ofimpact that could result in a pin misalignment or malfunction. However,this is an increasing need in the art for portable braille displays. Andportable braille displays often get jostled, bumped, or dropped in dayto day use. This is especially true for blind or low vision users. Evenwhen impacts do not result in a complete malfunction, they otherwiseinterfere with the strict tolerances that are required to provide anacceptable feel to the reader, as the misalignment of any components canbe perceived as static to the blind or low vision user. Even in theabsence of shocks and impacts, maintaining the precise positioning andalignment of tactile pins has proven to be very difficult with knowndisplay constructions.

Nor do the display designs of the background art lend themselves to easeof repair or maintenance. In particular, accessing the mechanical,electromechanical, or piezoelectric components of the cell is often verydifficult, if not impossible. As a result, the failure of any oneindividual braille cell often requires the wholesale replacement of allthe cells in the display. Alternatively, the failure of a single cellcan result in the entire display device having to be replaced. Theinability to service individual cells, or groups of cells, isproblematic as contaminants that build up on the pins must be removed orthe pins must be replaced upon excessive wear. Also, as noted above,pins are especially susceptible to damage upon encountering impacts orshocks.

Accordingly, there is a need in the art to improve the constructiondesign of braille displays. And there is a particular need in the artfor portable braille displays that are more durable and resistant toimpacts. There is also a need for braille displays with modularconstructions that allow the displays to be serviced and repaired.

However, in view of the prior art considered as a whole at the time thepresent invention was made, it was not obvious to those of ordinaryskill in this field that the identified improvements should be made norwould it have been obvious as to how to make the improvements if theneed for such improvements had been perceived.

SUMMARY OF THE INVENTION

One of the advantages realized by the display of the present disclosureis that it employs an impact and shock resistant construction.

A further advantage is attained by providing a portable braille displaythat can be dropped or bumped without causing the display tomalfunction.

Another advantage of the present braille display is that it utilizes ahousing with features that minimizes damage to internal components uponimpact.

Another advantage of the disclosed display is that it is constructed ina way that maintains the necessary tolerances of the tactile pins andprevents the pins and associated electromechanical elements fromshifting and malfunctioning.

Yet another advantage is realized by constructing the display in amodular fashion and that allows internal components to be accessed.

Another advantage is obtained by providing a display that can be easilyserviced and repaired.

A further advantage is achieved by providing a display construction thatavoids the wholesale replacement of all the tactile cells in the eventone such cell becomes damaged.

The foregoing has outlined rather broadly the more pertinent andimportant features of the present invention in order that the detaileddescription of the invention that follows may be better understood sothat the present contribution to the art can be more fully appreciated.Additional features of the invention will be described hereinafter whichform the subject of the claims of the invention. It should beappreciated by those skilled in the art that the conception and thespecific embodiment disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present invention. It should also be realized by thoseskilled in the art that such equivalent constructions do not depart fromthe spirit and scope of the invention as set forth in the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings in which:

FIG. 1 is a perspective view of the braille display of the presentdisclosure.

FIG. 2 is a top plan view of the braille display of the presentdisclosure.

FIG. 2A is a cross-sectional view taken along line 2A-2A of FIG. 2 .

FIG. 2B is an exploded view of the braille display of the presentdisclosure.

FIG. 2C is a sectional view of the braille display housing taken alongline 2C-2C of FIG. 2B.

FIG. 3 is a detailed view of the braille display subassembly of thepresent disclosure.

FIG. 3A is a detailed view taken from FIG. 3 .

FIG. 3B is a detail view taken from FIG. 3 with the glob top removed.

FIG. 4 is an additional view of the braille display subassembly of thepresent disclosure.

FIG. 5 is a perspective view of the USB assembly of the presentdisclosure.

FIG. 6 is a perspective further view of the USB subassembly of thepresent disclosure.

FIG. 7 is a detailed view showing the USB subassembly in position uponthe motherboard of the display.

FIG. 8 is an interior view of one of the end caps of the braille displayof the present disclosure.

FIG. 9 is a further view of the end cap and the associated snaplock ofthe present disclosure.

FIG. 10A is a detailed view taken along line 10A-10A of FIG. 9 .

FIG. 11 is a detailed view of the electrical connector positioned uponthe underside of one of the backplanes.

Similar reference characters refer to similar parts throughout theseveral views of the drawings.

PARTS LIST 20 Braille Display 22 Main Housing 24 Subassembly 26 FrontPanel 28 End Caps 32 Individual Cell Compartments 34 Upper Surface ofMain Housing 36 Braille Keys 38 Cursor Router Keys 42 Spacer Bar 44Rocker Keys 46 Panning Buttons 48 Upper Cover of Main Housing 52 LowerTray of Main Housing 54 Bimorph Reeds 56 Tactile Pins 58 Tactile Plane62 Motherboard 64 Backplanes 65 Shift Registers on Backplanes 66 BatteryHousing 68 Flex Cable for Motherboard 72 Anchor in End Cap 74 Slit inEnd Cap 76 Molded Opening in End Cap 78 Male Ridge in Molded Opening 82Back of Subassembly 84 Flex Cables for Shift Registers 86 Glob Tops 87Electrical Connector on Top of Backplane 88 USB Assembly 90 USBConnector 92 Over Molded Housing for USB 94 Female Channel in USBHousing 96 Flex Cable for USB Assembly 98 Snap Lock 100 Screw 102L-Shaped Housing for Snap Lock 104 Upward Post of Snap Lock 106 Downwardfoot of Snap Lock 108 Bottom Surface of Backplane 112 Male ElectricalConnector on Backplane 114 Female Electrical Connector on CellCompartment

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

This disclosure relates to a braille display that employs a modularconstruction and that is impact resistant. The impact resistance isachieved, in part, by molded and resilient end caps. Each end capincludes a centrally positioned slit that functions in absorbing lateralimpacts to the display. The impact resistance is further achieved by anassociated USB connector that is secured within an over molded outerhousing. Modularity is achieved by way of a subassembly that isreleasably secured within the interior of an outer housing. Thesubassembly, in turn, includes a series of individual braille cellcompartments that are arranged in groups. Each group of cellcompartments is controlled by an associated shift register. This allowsan individual shift register to be replaced by removing only theassociated cell compartments.

Braille Subassembly

With reference to FIG. 1 the braille display 20 of the presentdisclosure is illustrated. Display 20 includes a main housing 22, asubassembly 24, a front panel 26, and opposing end caps 28. Subassembly24, in turn, is formed from a number of discrete braille cellcompartments 32. In the depicted embodiment, 40 individual cellcompartments 32 are included for generating 40 discrete braillecharacters. Main housing 22 includes an upper surface 34 with an arrayof braille keys 36 and cursor router keys 38. Front panel 26 isreleasably secured to the front of main housing 22. Additional controlbuttons, such as a spacer bar 42, opposing rocker bars 44, and panningbuttons 46 are arranged along front panel 26. Those of ordinary skillwill appreciate how these controls can be used to orient the cursor ofthe display. Alternatively, these controls can be assigned uniquefunction as directed by the user.

With reference to the cross sectional view of FIG. 2A, it can be seenthat main housing 22 is formed from two interlocking pieces.Specifically, housing 22 includes an upper cover 48 and a lower tray 52that can be releasably coupled by way of a friction fit or via a seriesof peripherally located screws. Main housing 22 includes an interiorarea and an opening within its forward extent. Subassembly 24 isdimensioned to fit within the interior area of main housing 22. Therelationship between main housing 22 and subassembly 24 is bestillustrated with reference to the exploded view of FIG. 2B. Namely, byremoving front panel 26, subassembly 24 can be accessed and removed.This, in turn, allows individually cell compartments 32 to be accessedfor replacement or repair as needed.

The depicted subassembly 24 includes a series of 40 interconnected cellcompartments. However, this disclosure is not limited to any particularnumber of cell compartments and those of ordinary skill will appreciatethat 20 or 80 cell arrangements would also benefit from the discloseddesign. Regardless of the number included, each cell compartment 32 is afully contained component that includes all the parts needed to generatean individual braille character. In particular, each compartment 32preferably includes 8 bimorph reeds 54 with associated tactile pins. Inthe preferred embodiment, 8 reeds 54 are included. A tactile pin 56 ispositioned at the end of each reed 54. These pins 56 are registered withapertures formed within a tactile plane 58 at the upper surface ofsubassembly 24. Tactile plane 58 constitutes a uniform cell cap for theunderlying braille cells 32. Plane 58 operates to hold the 40 cellstogether and in proper alignment. It also presents a uniform and smoothfeel to the user. Each cell compartment 32 can be individually driven todisplay a particular braille character consisting of an eight pin array.However, it is also within the scope of the present disclosure toinclude cell compartments with six or fewer pins.

For an eight pin array, an instruction set consisting of 8 inputs isprovided to an associated cell compartment 32. This instruction set canbe provided from a motherboard 62 located within housing 22. The inputsspecify the up or down state of each pin 56 in the array, and thus thecharacteristics of a specific braille character, and the characteristicof a complete braille row. In one aspect of the present disclosure, aseries of backplanes 64 are used to route instructions to a subset ofcell compartments 32. In the depicted embodiment, the backplanes 64include an on-board shift register 65, or integrated circuit, that isused to provide instructions to a subset of 8 cell compartments 32. Theshift registers 65 are protected via a glob top 86 positioned over topof the backplane 64. Glob top 86 seals the shift register 65 upon thebackplane 64 and prevents it from being damaged or contaminated. Thus,the shift register 65 associated with each backplane 64 is capable ofproviding an instruction set with 64 inputs. For a display with 40 cellcompartments (note FIG. 2B), a total of five backplanes 64 withassociated shift registers 65 are needed. Nonetheless, the presentdisclosure is not limited to the use of five backplanes 64, anddifferent numbers of backplanes can be utilized as needed.

The instructions, or inputs, to display 20 will normally be provided tomotherboard 62 from an external host device, such as a phone, laptop,desktop, or tablet computer (not shown). The connection between theexternal device and display 20 can be accomplished via a wired orwireless connection. The host device will translate visible text orgraphics into corresponding braille characters. The translation can beaccomplished by either the operating system or a screen reader residenton the host device. The braille characters will be expressed as inputsto the cell compartments 32. These inputs are transferred to cellcompartments 32 via motherboard 62 and shift registers 62 in a daisychain fashion (described hereinafter). It is also within the scope ofthe present disclosure for instructions to be generated from motherboard62, thereby eliminating the need for an external device.

In one aspect of the disclosure, subassembly 24 is removably positionedwithin the opening of main housing 22. Main housing 22 also contains abattery housing 66 for storing the battery that supplies power to themotherboard 62 and other internal components of display 20. Housing 66assists with impact resistance by protecting the power supply fromdamage. Subassembly 24 is positioned within main housing 22 in such waythat it can be easily removed for service and repair. A flex cable 68preferably provides electrically communication between subassembly 24and motherboard 62 within main housing 22. Additional fasteners, such asscrews or detents, can be provided to releasably, but securely, mountsubassembly 24 within main housing 22. Furthermore, as illustrated inFIG. 2B, front panel 26 is positioned over the forward opening of mainhousing 22 to secure subassembly 24 in place within main housing 22.

End Caps

Main housing 22 is further secured by way of a pair of end caps 28. Eachend cap 28 includes an interior face that is positioned over one of thefirst or second ends of main housing 22. A portion of each interior faceextends into the main housing. The interior face includes an anchor 72that is employed in locking the associated end cap 28 in place via asnap lock assembly (described below). Each end cap 28 is overmolded,being formed from two distinct components that are formed in separateprocesses. The first component is the inner core of the end cap 28. Thisinner core is formed from a hard plastic that is dimensionally accurateand relatively hard. Suitable materials include any of a variety ofimpact resistant plastics, such as thermoplastic polymers. AcrylonitrileButadiene Styrene “ABS” plastics are suitable. ABS/Polycarbonate blendscan also be employed. A Cycoloy™ Resin C6600 from SABIC ChemicalManufacturing Company is a preferred material for the inner core. Thesecond component of the end cap 28 is an outer, and softer, housing,that surrounds the inner core. The outer housing is formed from a softliquid rubber that cures at a relatively low temperature. Athermoplastic polyurethane (“TPU”) is preferred for the outer housing.The second material is designed to be soft so as to absorb impacts andreduce shocks to the internal components of the device.

Regardless of the materials used, each end cap 28 is formed with acentrally located slit or opening 74. Opening 74 extends fully throughboth the inner and outer components of end cap 28. The resilientmaterial of each end cap 28, its enlarged size, and centrally locatedslit 74, all function in giving the end cap 28 a high degree ofresilience. This, in turn, gives display 20 lateral “bumpers.” As aresult, lateral impacts and bumps can be absorbed by the end cap 28 andare not transferred to main housing 22, or more importantly, theinterior components. This, in turn, prevents the bimorph reeds 54, pins56, and other electromechanical elements from becoming misaligned ordamaged. One of the two end caps 28 further includes a molded opening 76for an electrical connector such as a USB port 90. Opening 76 includes araised peripheral male ridge 78 that is used in properly aligning theUSB connector 90 to housing 22 in a manner described in more detailhereinafter.

Back Planes

With reference now to FIGS. 3 and 3A, the back edge 82 of subassembly 24is depicted. A series of backplanes 64 are equally positioned along backedge 82. In the depicted embodiment, five backplanes 64 are positionedin end to end relationship. The upper surface of teach backplane 64includes an electoral connector 87 and a glob top 86. As noted, glob top86 is included to protect an associated shift register 65. Shiftregister 65 is hidden by glob top 86 in FIG. 3A. However, in FIG. 3B,glob top 86 is removed to illustrate the underlying shift register.Electrical connectors 87 can be used to interconnect adjacent backplanes64 via flex cables 84. An additional flex cable connects backplanes 64to the adjacent motherboard 62. In this way, backplanes 64 receiveinstructions from the motherboard 62 in a “daisy chain” fashion. Flexcables 84 can be uncoupled from one another as needed.

Each backplane 64 further includes a bottom surface 108 with a series ofmale electrical connectors 112. Each of these connectors 112 fits into acorresponding female electrical connector at the end of an associatedcell compartment 32. In a preferred but non-limiting embodiment, eachbackplane 64 includes five male connectors 112 along its bottom face. Inthis manner, the shift registers 65 associated with the backplanes 64can transmit instructions from motherboard 62 to the associated tactilecell 32. An individual cell 32 can be selectively unplugged from thebottom of the associated backplane 64 as needed. Since five backplanes64 are included, and each backplane 64 controls the operation of 8associated tactile cells 32, a total of 40 cells can be controlled.

The daisy chain connection permits instructions to flow into cellcompartments. Once all necessary inputs are received within one shiftregister, the succeeding instructions flow into the immediately adjacentshift register and so on. If the connection from the subassembly 24 tomotherboard 62 is on the right side, shift registers 65 will receiveinstructions from left to right (when facing the front of display 20).Instructions will be received in the opposite direction if the flexcable is connected to the opposite side of motherboard 62. The precludesthe instructions from having to be addressed or associated with aparticular shift register or group of tactile cells. This arrangementalso allows an individual cell compartment 32 to be removed and replacedfrom subassembly 24 as needed without disturbing the remaining of thecell components 32. Again, however, the present disclosure is notlimited to the use of any particular number of cell compartments 32. Theuse of fewer than 40 cell compartments would necessarily entail fewershift registers 64.

USB Assembly

With reference to FIGS. 7 and 8 the USB assembly 88 is described next.USB assembly 88 is employed in both protecting the USB connector 90 fromimpacts and shocks and also in properly orienting the USB connector 90within the side of main housing 22. Although this feature is disclosedin connection with a USB connector 90, any number of electricalconnectors can be used. These connectors can include, for example, CATcables, network cables, MGA, VGA, MIDI, or of a variety of otherparallel or serial ports. However, in the depicted embodiment, a USBType C connector 90 is employed. In accordance with the disclosure, theconnector is housed within an over molded outer housing 92. Housing 92is preferably formed from an impact resistant plastic. Any of a varietyof thermoplastic polyurethane elastomers (TPUs) can be used. APellethane 2363-80AE plastic from Lubrizol Corporation is preferred.

As illustrated, outer housing 92 includes a female channel 94 extendingabout its peripheral extent. This channel 94 cooperates with thecorresponding male ridge 78 within the USB opening 76 in the end cap.This allows the USB connector 90 to be oriented properly with respect tohousing 22. Yet, it also affords a limited degree of movement and impactresistance along with the over molded housing 92. Further impactresistance is achieved by connecting the USB connector 90 to motherboard62 by way of a flex cable 96. This mechanically isolates motherboard 62from connector 90. All of these features minimize any damage to theconnector 90 in the event of impacts or display device 20 being dropped.

Snap Lock Assembly

The snap lock 98 arrangement is next described in conjunction with FIGS.9 and 10 . Although a single snap lock 98 is depicted, the displayutilizes two snap locks 98, one at either end of display 20. Each snaplock 98 ensures that its adjacent end cap is secured to the main housing22. Snap locks 98 also transfer forces from the upper cover 48, to thelower tray 52 of the housing, and downward to the adjacent anchor 72 inend cap 28. Because peripheral spacing within the device is tight, eachsnap lock 98 allows associated end cap 26 to be secured without the needfor additional bolts or other threaded fasteners. Each snap lockincludes an L-shaped housing 102 with both an upwardly extending post104 and a downwardly extending foot 106. A screw 100 is used to positionthe snap lock 98 housing 102 within the lower tray 52 of main housing22. Notably, only a minimal screw force is needed to position housing102 within tray 52. By affixing screw 100 in this fashion the downwardlyextending foot 104 of snaplock 98 impinges upon the anchor 72 of the endcap 26. Once upper cover 48 of main housing 22 is properly fastened (viaadditional peripheral fasteners), upper cover 48 will apply downwardpressure onto upward post 104. This pressure, in turn, applies moreforce upon downward foot 106 and the underlying anchor 72. All of thispositively secures L-shaped housing 102 and associated end cap 28. Thisallows forces between upper and lower covers (48 and 52) to provide thenecessary downward force on anchors 72. This fastens all the majorcomponents of display 20, while at the same time eliminating internalfasteners and affording a greater degree of tolerance.

The present disclosure includes that contained in the appended claims,as well as that of the foregoing description. Although this inventionhas been described in its preferred form with a certain degree ofparticularity, it is understood that the present disclosure of thepreferred form has been made only by way of example and that numerouschanges in the details of construction and the combination andarrangement of parts may be resorted to without departing from thespirit and scope of the invention.

What is claimed is:
 1. An impact resistant modular braille displaydevice comprising: a main housing including forward and rearwardextents, and first and second opened ends, an upper cover with a topsurface extending between the first and second opened ends, a series ofbraille keys formed within the top surface, a lower tray releasablycoupled to the upper cover, an opening formed within the forward extentof the main housing, a motherboard positioned between the upper coverand lower tray, a removable faceplate positioned over the forwardopening of the main housing; a pair of end caps, each end cap includingan inner core of a first plastic material and an outer housingsurrounding the inner core and that is formed from a second plasticmaterial, the first plastic material being harder than the secondplastic material, a slit formed along a top surface, the slitfunctioning as a shock absorber for the display device, each inner corebeing positioned within one of the first and second opened ends of themain housing; an opening for an electrical connector formed within oneof the two end caps, the opening including an inner periphery with araised ridge; an electrical connector including a housing formed from animpact resistant plastic and including a female recess about itsperiphery, the raised ridge of the opening being positioned within thefemale recess to properly orient the connector within the main housing,the connector further including a flex cable interconnecting themotherboard to the connector.
 2. The display device as described inclaim 1 wherein the inner core of each end cap include a protrudinganchor.
 3. The display device as described in claim 2 wherein a snaplock is associated with each end cap, each snap lock including a housingwith an upwardly extending post and a downwardly extending foot, a screwsecuring the housing to the lower tray of the main housing, whereby thedownwardly extending foot impinges upon the associated anchor to securethe end cap to the main housing.
 4. The display device as described inclaim 1 wherein the faceplate includes a space bar, opposing rockerbars, and panning buttons.
 5. The display device as described in claim 1further comprising a subassembly positioned within the forward openingof the main housing, the subassembly including a series ofinterconnected cell compartments, each cell compartment includingforward and rearward ends and housing a series of bimorph reeds, eachbimorph reed supporting an associated tactile pin, the rearward ends ofthe cell compartments forming a back surface.
 6. The display device asdescribed in claim 5 further comprising a series of five backplanespositioned in end to end relationship along the back surface, eachbackplane including a shift register that functions to provideinstructions to a group of associated cell compartments, a series offlex cables electrically interconnecting the five backplanes to themotherboard, whereby an individual shift register and its associatedcell compartments can be removed from the subassembly without disturbingthe remaining cell compartments.
 7. A braille display device comprising:a housing including forward and rearward extents, and first and secondends, an upper cover with a top surface extending between the first andsecond opened ends, a series of braille keys formed within the topsurface, a lower tray releasably coupled to the upper cover; a pair ofend caps, each end cap secured over one of the first or second ends ofthe housing, each end cap including a slit formed along a top surface,the slit functioning as a shock absorber for the display device.
 8. Thebraille display device as described in claim 7 further comprising anopening for an electrical connector formed within one of the two endcaps, the opening including an inner periphery with a raised ridge. 9.The braille display device as described in claim 8 further comprising anelectrical connector including a housing formed from an impact resistantplastic and including a female recess about its periphery, the raisedridge of the opening being positioned within the female recess toproperly orient the connector within the main housing.
 10. The brailledisplay as described in claim 9 further comprising a flex cableinterconnecting connector to a motherboard.
 11. The braille display asdescribed in claim 10 wherein an opening is formed within the forwardextent of the main housing, the motherboard positioned between the uppercover and lower tray, a removable faceplate positioned over the forwardopening of the main housing.
 12. The braille display as described inclaim 7 wherein each end cap is formed from an inner core of a firstplastic material and an outer housing surrounding the inner core andthat is formed from a second plastic material, the first plasticmaterial being harder than the second plastic material.